Welcome to the Shopify Community! Are you able to share a screenshot of what you are seeing on the product page? I am unable to view your website, as I don't have the password!
To set up a compare price, you need to put the original (full) price in the Compare at price field, and the new (sale) price in the Price field. For example, if you want the product to be $0.00 (free), but show that it used to be $5.00, here's what it would look like on the product details page:
This then will display on the storefront like this:
As you can see, the product is showing as $0.00, but we can see the old price crossed out.
Let me know how this goes. If you're still having troubles, screenshots of what your seeing are helpful. As well, please share the theme you are using!
Hilary | Community Manager @ Shopify - Was my reply helpful? Click Like to let me know! - Was your question answered? Mark it as an Accepted Solution - To learn more visit the Shopify Help Center or the Shopify Blog